The technical field of this invention is the topical application of personal care agents and, in Particular, methods and compositions for topical application of sunscreens.
In recent years, the public has become increasingly aware of the harmful effects of overexposure to the sun, Particularly the ultraviolet components of sunlight. Painful sunburn is a common result of short-term overexposure. Additionally, wrinkling and premature aging of the skin, and even cancer, can result from chronic overexposure.
Sunscreens typically operate by absorbing ultraviolet radiation. Compositions useful as sunscreens should disperse easily onto the skin, closely adhere to the skin, resist penetration through the skin, and resist shedding by perspiration or by immersion in fresh or salt water.
Unfortunately, most sunscreens do not fully satisfy these requirements in terms of durability and efficacy. Often, sunscreen compositions are quickly shed from the skin or absorbed into the lower layers of the skin where their radiation blocking activity is markedly reduced.
There exists a need for better sunscreen compositions, particularly for economical, long-term Protection from the harmful effects of ultraviolet radiation.